The invention relates to a method for transmitting vehicle data of a motor vehicle to a memory element, which can be removed from the motor vehicle, wherein the vehicle data are transmitted to the memory element and stored in the memory element at least twice during the course of a drive.
It is known to transmit vehicle data to a removable memory element and to store the vehicle data on the memory element. DE 199 19 501 A1 discloses to store operation-dependent vehicle data in a vehicle key having a transponder. The operation-dependent data are transmitted to the key by the electronic display unit via the electronic immobilizing system and stored in a memory element of the key.
Further, it is known from DE 102 22 141 A1 to wirelessly transmit vehicle data to a memory medium for storage. At the beginning of travel, the vehicle data are transmitted from the motor vehicle to the storage medium and, as soon as new error data are detected during travel, either transmitted immediately or stored in a buffer memory. At the end of travel, changes of and/or additions to the data stored in the memory at the beginning of the drive are executed.
DE 10 2006 041 765 B4 discloses a method in which a kilometer reading of a motor vehicle is transmitted to a memory element, and stored in the memory element, wherein only a kilometer reading which is greater than the last stored kilometer reading can be stored.
During the drive, the kilometer reading is transmitted at defined intervals to the memory element in the wireless key, where it is only stored however when the received value exceeds the one which was stored last. This means that smaller kilometer readings, for instance as a result of a manipulation on the vehicle, are not registered in the key. As a result, after manipulation involving a turning back of the kilometer reading, this kilometer reading is recorded only in the vehicle but not in the key.
As the kilometer reading is stored in the vehicle but not in the key following a turning back of the kilometer reading, a difference exists between the key kilometer reading and the vehicle kilometer reading for a period of time, allowing detection of the manipulation. After a certain time however, the vehicle kilometer reading catches up with the key kilometer reading again, and a manipulation is no longer detectable.
DE 198 21 696 A1 discloses a method for the transfer and storage of information, which is established by a number of time sequential pulses, especially of a distance traveled by the vehicle, in which method a counter unit counts incoming pulses, the number of pulses which is present after a predetermined period of time is transferred to the receiver unit in encrypted form according to an encryption algorithm, the decoded number, which is decoded according to the same encryption algorithm, is determined in the receiver unit, and the sum of all numbers is stored.
DE 199 19 501 B4 describes a device for storing operation-dependent vehicle data in a removable memory element.
The object of the present invention is therefore to improve a method of the type mentioned above such as to protect the memory unit against a manipulation of the kilometer reading.